1. Field
The following description relates to a Schottky diode having a single floating region or multiple floating regions. The following description also relates to a Schottky diode configured to increase a breakdown voltage (BV) compared to that of a an alternative Schottky diode through use of a single floating guard ring or multiple floating guard rings and an additional element isolation layer or shallow trench isolation (STI) located between the floating guard ring or rings and a cathode region for the Schottky diode.
2. Description of Related Art
A Schottky diode is typically used to good effect as a switching or a rectifying device in a semiconductor circuits. A Schottky diode, as discussed herein is a diode that is formed as a combination of a semiconductor portion and a metal portion. A metal anode enables the Schottky diode to have higher switching performance than a general alternative PN junction diode.
This result of higher switching performance occurs because when a forward bias voltage is applied to the Schottky diode, a Minority Carrier Injection (MCI) does not occur, by contrast with the alternative PN junction diode. That is, the Schottky diode has an advantage as a component of having a very short recovery time because current flows by using majority carriers, not minority carriers. Thus, there is no storage effect. Moreover, the turn-on voltage of a Schottky diode is lower than that of comparable PN junction diodes.
By contrast, the breakdown voltage of conventional Schottky diodes is not high for many integrated circuit applications. In particular, in some applications, a Schottky diode has been integrated into a Bipolar-Complementary Double Diffused Metal Oxide Semiconductor (CDMOS)-Double Diffused Metal Oxide Semiconductor (DMOS) (BCD) process that is an example technology of an integrated circuit. However, a Schottky diode with a higher breakdown voltage than a Schottky diode of an alternative art is potentially desirable. However, introduction of a simple guard ring or a shallow trench isolation (STI) into the Schottky diode does not improve its breakdown voltage for BCD technology.